In the attempt to conserve energy there is one source of wasted energy that is often forgotten and neglected. This is the heat contained in the water of a domestic sewer and waste water system. While heat-exchangers have been developed for transferring heat from many normal sources of heat waste to other areas of the home, such heat-exchange units are not particularly adaptable to use with waste water. This is because waste water contains solids that are of such a diverse and non-homogeneous character. Attempts to operate conventional heat-exchange units for the purpose of transferring heat from waste water and sewage to incoming water have been less than effective because of the coating and sludging character of the waste. These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding object of the invention to provide a heat recovery system particularly adapted to use with domestic waste water.
Another object of this invention is the provision of a heat-exchange unit in which the primary liquid is subjected to considerable agitation.
A further object of the present invention is the provision of a heat-exchange system in which one of the liquids is carried in a very long flow path about a short path of flow of the other liquid.
It is another object of the instant invention to provide a heat-exchange system for use where temperature differential between the primary and secondary fluids is low.
A still further object of the invention is the provision of a heat recovery system for insertion in a domestic sewer system, which unit is simple and rugged in character, which is inexpensive to manufacture, and which is capable of a long life of useful service with a minimum of maintenance.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.